It's been the hottest spring ever in the contiguous US—by far: The months of March, April, and May clocked in at two degrees warmer than the previous record. With an average temperature of 57.1 degrees, it was five degrees hotter than the average spring. At 64.3 degrees, May alone was the second-hottest since records began; only 1934 was warmer. On top of that, the first five months of this year, as well as the 12 months since last June, have been the hottest ever recorded; experts cite "persistent weather patterns," the AP reports. (More Spring stories.)